The Estimation of Compressive Stress Level in Brick Masonry Using the Flat-jack Method

Łątka, Dawid; Matysek, Piotr

doi:10.1016/j.proeng.2017.06.213

Cited by 25 publications

(12 citation statements)

References 8 publications

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“…Methods which directly determine compressive or shear strength of a wall, are commonly assumed as destructive testing (DT). Those studies consist in testing fragments of a masonry wall [2,3]. Destructive (direct) techniques use fragments of walls or flat jacks in bed joints, and deliver test results in the form of compressive strength of the wall f k .…”

Section: Introductionmentioning

confidence: 99%

Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

2019

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Minor-destructive (MDT) and non-destructive (NDT) techniques are not commonly used for masonry as they are complex and difficult to perform. This paper describes validation of the following methods: semi-non-destructive, non-destructive, and ultrasonic technique for autoclaved aerated concrete (AAC). The subject of this study covers the compressive strength of AAC test elements with declared various density classes of: 400, 500, 600, and 700 (kg/m3), at various moisture levels. Empirical data including the shape and size of specimens, were established from tests on 494 cylindrical and cuboid specimens, and standard cube specimens 100 mm × 100 mm × 100 mm using the general relationship for ordinary concrete (Neville’s curve). The effect of moisture on AAC was taken into account while determining the strength fBw for 127 standard specimens tested at different levels of water content (w = 100%, 67%, 33%, 23%, and 10%). Defined empirical relations were suitable to correct the compressive strength of dry specimens. For 91 specimens 100 mm × 100 mm × 100 mm, the P-wave velocity cp was tested with the transmission method using the ultrasonic pulse velocity method with exponential transducers. The curve (fBw–cp) for determining the compressive strength of AAC elements with any moisture level (fBw) was established. The developed methods turned out to be statistically significant and can be successfully applied during in-situ tests. Semi-non-destructive testing can be used independently, whereas the non-destructive technique can be only applied when the developed curve fbw–cp is scaled.

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Section: Introductionmentioning

confidence: 99%

Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

2019

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“…The indicator for the absolute value of the network output ( y NNi |) guarantees that each of them will be in the range of Absolute Relative Error from zero to maximum absolute Relative Error [77,78]. Consequently, it gives information about the absolute value of the maximum possible error of the mathematical model [79][80][81] represented by the already taught neural network. This criterion only includes data for the testing stage.…”

Section: The Network Structure and Its General Equationmentioning

confidence: 99%

Towards Characterization of Indoor Environment in Smart Buildings: Modelling PMV Index Using Neural Network with One Hidden Layer

Dudzik

2020

Sustainability

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Modelling of comfort with the use of neural networks in modern times has become extremely popular. In recent years, scientists have been using these methods because of their satisfactory accuracy. The article proposes a method of modelling feedforward neural networks, thanks to which it is possible to obtain the most efficient network with one hidden layer in terms of a given quality criterion. The article also presents the methodology for modelling a PMV index, on the basis of which it can be demonstrated whether the network will work properly not only on paper but in reality as well. The objective of this work is to develop a performance model allowing the effective improvement of all electrical and mechanical devices affecting the energy efficiency and indoor environment in smart buildings. To achieve this, several attributes of indoor environment are included, namely: air leakage as a connection to the outdoor environment, but also as uncontrolled component of energy, ventilation as delivery and distribution of fresh air in the building space, individual ventilation on demand indoor air quality (IAQ) in the dwelling or as a personal IAQ control, source control of pollutants in the building, thermal comfort, temperature, air movement and humidity control (humidity modifiers, i.e., buffers different from the air conditioning radiation from cold and hot surfaces bringing forward a question about the strategy of the process control. One may either develop a series of control models to be synthesized later or one can use one over-arching characteristic and use its components for operating the control system. The paper addresses the second strategy and uses the concept of PMV for a criterion of broadly defined thermal comfort (including ventilation and air quality).

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“…If it is not possible to cut out masonry samples from the existing structure, masonry strength can be estimated using the flat-jack method [9,10,11]. In the first step, the mortar from two bed joints is removed; flat jacks are then placed in these joints.…”

Section: Determination Of the Masonry Compressive Strength Based On Lmentioning

confidence: 99%

The reliability of masonry structures – evaluation methods for historical buildings

2018

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In this paper, selected issues regarding the assessment of the reliability of masonry structures in existing buildings, including historical buildings, are presented. The specifics of diagnostics and computational analysis of these types of objects are highlighted. Methods of determining the masonry compressive strength in existing structures while taking into account the reliability theory are given. A combination of nondestructive and destructive tests is proposed as the basis for determining the masonry strength parameters. Practical solutions for determination of design masonry strength were given which can be used in assessing the safety of massive brick walls and pillars constituting important structural elements of existing masonry buildings.

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The Estimation of Compressive Stress Level in Brick Masonry Using the Flat-jack Method

Cited by 25 publications

References 8 publications

Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

Towards Characterization of Indoor Environment in Smart Buildings: Modelling PMV Index Using Neural Network with One Hidden Layer

The reliability of masonry structures – evaluation methods for historical buildings

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